Method of treating oily smoke, fumes, vapor or ordors

ABSTRACT

The invention relates to a method for treating oily smoke, fumes, vapor or odors produced when cooking. According to this method, the oily smoke, fumes, vapor or odors coming from cookers placed over an oven will be drawn and mixed with a part of air to form gaseous mixture under the action of drawing fan. Then, the formed gaseous mixture will be forced to enter at least one preheating region. In the said preheating region, the said gaseous mixture is preheated. After preheated, the said gaseous mixture is forced to enter at least one heating source region of the said oven. A part of thermal energy provided by the heating source located in the center of the said heating source region is used for preheating the said gaseous mixture filling in the said preheating region. In the heating source region the temperature of the preheated gaseous mixture will raise to a high enough level so that the pollutants contained in the said gaseous mixture can be decomposed and/or fully reacted with the oxygen in the gaseous mixture. A part of thermal energy provided by the said heating source is used for initiating and/or accelerating the decomposition and/or oxygenation of the pollutants. Then, the products of the said decomposition and/or oxygenation reactions and the un-reacted matter contained in the said gaseous mixture are discharged from the said heating source region by passing through at least one filter. In the present invention, the said heating source can be a gas, fuel oil, electric or coal range. When the heating source is gas, fuel oil or coal range, the oxygen contained in the said gaseous mixture can accelerate and improve the combustion of gas, fuel oil or coal. On the other hand, the oxygenation of pollutants contained in oily smoke, fumes, vapor and odors can also have some contribution to maintain the high temperature of the said heating source region because their oxygenation reactions are all exothermal reactions.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] REF-CITED: U.S. and French PATENT DOCUMENTS (please see FormP.T.O.-1449) 2,224,945 7/1937 *B. Ames 55#42 2,106,935 10/1972 *DamonFrede F24f 13/00 4,235,220 11/1980 *R. J. Hepner 98/115R 4,929,2585/1990 *Wang 55#86 5,027,790 7/1991 *Sheng 126#299R 5,154,742 10/1992*William 55#26B 5,359,990 11/1994 *Hsu 126#299E 5,470,365 11/1995 *Jang55#510 5,601,072 2/1997 *Hsu 126#299E

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not Applicable

REFERENCE TO A MICROFICHE APPENDIX

[0003] Not Applicable

BACKGROUND OF THE INVENTION

[0004] Most activities of humanity are carried out indoors. Thepollution of indoor environment can cause many kinds of disease.Preventing indoor environment pollution has been paid great attentionduring the past decades around the world. Oily smoke, fumes, vapor orodors and organic foul gases are main indoor pollution sources.

[0005] When cooking temperature is over 130° C., oily smoke will beformed from either animal oil or vegetable oil. The oily smoke can fillthe air and harm the human respiratory system and circulatory system.Especially, when the cooking temperature reaches 230° C.-280° C., somecarcinogens will produce from vegetable oily smoke. In Taiwan andChinese mainland, housewives have much bigger possibility of lung cancerand esophagus cancer than occupational women do. The reason is thathousewives often cook and most Chinese families like stir-fried foods,for which the vegetable oil must be heated to a higher temperature. So agreat quantity of oily smoke and fumes can be formed and inevitablyabsorbed by the housewives. The irritative vapor or odors produced frompepper, Chinese prickly ash or other flavorings is also harmful to thehousewives.

[0006] In order to remove the oily smoke, fumes, vapor or odors producedwhen cooking, the conventional method is drawing them with a powerfulexhauster assembled above the cooker, then discharging them into outdooratmosphere or into sewers. This method has several shortages.

[0007] First, in order to discharge the oily smoke, fumes, vapor orodors into outdoor atmosphere or sewers a complex pipe system connectingexhauster and chimney or sewer needs to be designed and built whenbuilding a new house, which must increase the cost of the house. Ifpurchasing a house without the pipe system, the host has to rebuild itspending a lot of time and money. If renting this kind of house, thetenant either change his or her dietary habits, which is veryuncomfortable for Chinese, Vietnamese, Thailand or other Asia people wholike fried foods, or endures the suffering caused by oily smoke, fumes,vapor or odors.

[0008] Second, in order to decrease the harm of oily smoke, fumes, vaporor odors, doctors suggested that the height from the drawing fan to thecooker should be as small as possible (not over 40 cm) in order toexhaust the oily smoke, fumes, vapor or odors more completely. However aso small height must hinder the cooking operation. A good idea is thatthe height can be changed very easily. In other words, at the beginningof cooking when a great quantity of oily smoke, fumes, vapor or odorsoccurs, we can let the exhauster very close to the cooker. After pouringfoods into the cooker, we can raise the exhauster for the convenientoperation because the quantity of oily smoke, fumes, vapor or odors atthat time has been reduced very much. Unfortunately, the height ofexisting oily smoke exhausters can not be changed after installed andconnected with the pipe system.

[0009] Thirdly, a great quantity of oily smoke, fumes, vapor or odorsdischarged from kitchens and restaurants will result in serious air andwater (if the smoke is discharged from sewers) pollution. Especially,the oily smoke, fumes, vapor or odors may enter the windows or balconiesof neighbors' houses.

[0010] Finally, the whole pipe system and the drawing machine willinevitably be polluted by residual oily liquid. After using for a periodof time, in general, four or five weeks, the users had to askprofessionals to dismount the system and machine in order to clean them,then assemble the same. This work is obviously time-consuming,labor-some and expensive.

[0011] In order to solve the latter two problems as above mentioned,many inventors proposed a variety of methods. U.S. Pat. No. 4,929,258disclosed a method used to purify oily smoke pollution, according to themethod the smoke pollutant can be introduced to several hollow tanksfilled with plenty of water droplets, then contact with these waterdroplets to condense inside tanks and can be purified without smoke andodor. U.S. Pat. No. 5,027,790 described an oil-removal structure forrange hoods, in which a water container formed integrally with anair-guiding case receiving two fans. At least one electric thermalelement downwardly passes a top house and extends into the watercontainer to heat the water. The oily residual can be melted and dropdown to a collector. U.S. Pat. No. 5,154,742 described an oil mist and asmoke collector, from which the contaminated air is driven against aplanar impingement plate arranged to be struck with a glancing blow ofsuch force as to remove a substantial portion of the contaminates byimpact. U.S. Pat. No. 5,359,990 proposed a similar oily smoke treatingand exhaustive device for cooking equipment. It has an upper smokehousing, two vertical passageways formed by three vertical platesextending down and up from the housing for oily smoke produced incooking to be showered with water to let oil in the smoke be mixed withwater and drop down into a separating tank. U.S. Pat. No. 5,470,365disclosed a smoke exhauster. A filtration member is disposed in theexhauster to purify the fume so as to reduce the discharge of the airpollutant into the atmosphere. U.S. Pat. No. 5,601,072 suggested anatomizing device for oily smoke. Oil contained in the oily smoke can beseparated into oil particulate when passing through several atomizingplates mounted in the passage. A water tube is disposed above theatomizing plates for absorbing the oil particulate, then, the oilbecomes liquefied oil that is drained.

[0012] If using the above methods to reduce the pollutants contained inthe oily smoke, one has to add some complex equipment, such as thecooling condenser system and the atomizing device described in U.S. Pat.No. 5,601,072. So the cost and maintenance charge must increase greatly.When using these methods shown in U.S. Pat. No. 4,929,258, U.S. Pat. No.5,027,790, U.S. Pat. No. 5,154,742, U.S. Pat. No. 5,359,990 and U.S.Pat. No. 5,601,072, although one does not need to mount speciallycomplex devices, only part of the pollutants contained in the dischargedoily smoke can be removed. If using the filtering methods described inU.S. Pat. No. 5,470,365, the flow of oily smoke driven by the exhausterwill decrease greatly, so more powerful drawing fans will be necessary.The cost of product and the maintenance fee can also rise. In especial,all of the above mentioned methods can not solve the first two problemsof existing oily smoke exhauster, i.e. the complex pipe system and theunchangeable height from the cooker to the drawing fans. Besides, thenoise caused by the exhauster is still a problem. As we all know, thelonger and more complex the pipe system is, the more powerful theexhauster should be, the bigger the noise must be.

[0013] U.S. Pat. No. 4,235,220 mentioned another cooking stove exhaustsystem, in which an activated charcoal filter was used to purify aircontained oily smoke. An electric heat element was used to activate thecharcoal at selective intervals of time, but not for treating the oilysmoke directly. U.S. Pat. No. 2,224,945 described a cooker, in which anelectrically energized source of glowing radiant energy was located inthe upper part of the cooking chamber. The radian heat coming from theelectric element was used for cooking. On the other hand, the radianheat within the cooking chamber was also used to clean the odor, fumesor smoke producing from cooking. The cooker has a complex constructionand a special electric element with a high power (should be over 1,000Watt for reaching 1500 to 1700 F), which may cause safety problems.Especially, the cooking operation, such as mixing food, frying otherside of a fish, is very difficult by using this cooker. When opening thecover of the chamber for cooking operation, we will endure the oilysmoke and the cooker will lose its self-cleaning function. Since thechamber must be closed when cooking, another shortage of this inventionis obvious. It is that the oxygen in the chamber is not enough foroxygenating the oily smoke and odor even though the temperature in thechamber may be very high. If the oxygen is not enough, a certain amountof carbon monoxide may produce, which is very harmful to the operator.

[0014] French patent 2,106,935 described a device for evaporating fumes,vapor, gas or odors directly or through a ventilation pipe. The drawnfumes, vapor, gas and odors are forced to pass through a hightemperature region, in which the high temperature is maintained by anextra electrically heating element. Therefore, the device needs an extraheating energy source. In order to obtain a better cleaning effect, thetemperature maintained in the said region must be high enough, theelectrically heating source must have a higher power, in general, higherthan 1,000 Watt. It is energy consuming and may cause some safeproblems. Another problem is the said heating region must long enough.Because the decomposition or oxygenation of fumes, vapor, gas and odorscan not be finished in a short time. The long and hot pipe may causeother problems, such as mounting, space limitation, thermal pollutionand safety.

BRIEF SUMMARY OF THE INVENTION

[0015] The present inventor has noticed the above mentioned annoyingproblems when using existing oily smoke exhausters to remove indoorpollution, and come up with a solution by designing a novel method andrelated devices used to effectively purify oily smoke, fumes, vapor orodors.

[0016] The invention relates to a method for treating oily smoke, fumes,vapor or odors produced when cooking. According to this method, the oilysmoke, fumes, vapor or odors coming from cookers placed over an ovenwill be drawn and mixed with a part of air to form a gaseous mixtureunder the action of drawing fan. Then, the formed gaseous mixture willbe forced to enter at least one preheating region. In the saidpreheating region, the said gaseous mixture is preheated. Afterpreheated, the said gaseous mixture is forced to enter at least oneheating source region of the said oven. In general, the heating sourceof the said oven is surrounded with the said preheating region, throughwhich the said heating source region can be formed between the saidheating source and the said preheating region. A part of thermal energyprovided by the said heating source located in the center of the saidheating source region is used for preheating the said gaseous mixturefilling in the said preheating region. After enter the said heatingsource region the temperature of the said gaseous mixture will raise toa high enough level so that the pollutants contained in the said gaseousmixture can be decomposed and/or fully reacted with the oxygen containedin the said gaseous mixture. A part of thermal energy provided by thesaid heating source is used for initiating and/or accelerating thedecomposition and/or oxygenation of the pollutants. Then, the productsof the said decomposition and/or oxygenation reactions and theun-reacted matter contained in the said gaseous mixture are dischargedfrom the said heating source region by passing through at least onefilter.

[0017] In the present invention, the said heating source can be a gas,fuel oil, electric or coal range. When the heating source is gas, fueloil or coal range, the oxygen contained in the said gaseous mixturefilling in the said heating source region can accelerate or improve thecombustion of gas, fuel oil or coal. On the other hand, the oxygenationof pollutants contained in oily smoke, fumes, vapor and odors can alsohave some contribution to maintain the higher temperature of the saidheating source region because these oxygenation reactions are allexothermal reactions. The higher the power of the heating source is, thehigher the temperature of the cooker will be, the more the quantity ofoily smoke, fumes, vapor or odors will be, thereby, the more the thermalenergy contribution produced from these oxygenation reactions must be.

[0018] The first object of the present invention is to provide a simplemethod for treating oily smoke, fumes, vapor or odors. As compared withexisting methods and devices, it can omit the complex pipe systemmounted for connecting the exhauster with chimney or sewers describingin the above mentioned patent documents. The pollutants contained in theoily smoke, fumes, vapor or odors can be decomposed and/or oxygenatedduring passing through the said heating source region of the oven. Theproducts of these reactions and un-reacted matters can be dischargeddirectly from the said heating source region without any need of pipesystem or special outlet.

[0019] The second object of the present invention is to provide a simplemethod for removing oily smoke, fumes, vapor or odors. Based on thismethod, an adjustable remover can be designed, when using it thedistance between the cooker and the drawing fan can be adjusted easilyfor various needs. When a great quantity of oily smoke, fumes, vapor orodors, such as deep-frying fishes, the drawing fan can be adjusted toclose the cooker. For common frying, the fan can be raised to keep abigger distance from the cooker for the convenient operation.

[0020] The third object of the present invention is to provide aneffective method to more thoroughly remove the pollutants contained inoily smoke, fumes, vapor or odors through chemical decomposition and/orreaction not physical methods, such as those shown in the abovementioned patent articles. The products of these reactions andun-reacted matter discharged from the said heating source region containlittle pollutants and have little harm to user's family and his or herneighbor.

[0021] The fourth object of the present invention is to provide a simplemethod for treating oily smoke, fumes, vapor or odors. By using it theheavy work of cleaning the complex pipe system can be avoided. Thedevice design based on this method can be disassembled easily for clean.

[0022] The fifth object of the present invention is to provide aconvenient method for treating oily smoke, fumes, vapor or odors.According to this method any cooking operation will not be affected. Thedevice designed based on the method can be moved to different ovens orheating sources very easily. Compared with the method and devicedescribed in U.S. Pat. No. 2,224,945, the present method and device donot need any cover for closing the cooker. Therefore, the cookingoperation will be convenient.

[0023] The further object of the present invention is to provide a safe,noiseless and energy-saving method for treating oily smoke, fumed, vaporor odors. It does not need any special or extra heating source to treatthese pollutants as that shown in French Pat. No. 2,106,935.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0024]FIG. 1 is a perspective view of one of the devices designed basedon the present invention, which is used to purify the oily smoke, fumes,vapor or odors produced from a cooker placed over an oven. The gaseousmixture of air and oily smoke, fumes, vapor or odors is drawn by adrawing fan and sent to the preheating region, then enter the heatsource region of the oven for decomposition and/or oxygenation. Aftercleaned, the said gaseous mixture is discharged from the said heatingsource region through a filter. In this case, the said heating source ofthe oven is a gas range. Therefore, the said heating source region is,in fact, a gas combustion region.

[0025]FIG. 2 is a 3-D section view of the heating source region shown inFIG. 1, in which the said heating source is a gas range and the saidheating source region is, in fact, a gas combustion region.

[0026]FIG. 3 shows a perspective view of another design based on thepresent invention, which is used to purify the oily smoke, fumes, vaporor odors produced from a cooker placed over an oven. In this design thesaid gaseous mixture of air and oily smoke, fumes, vapor or odors isdrawn by a drawing fan, then enter two preheating regions forpreheating, and then enter two heating source regions for decompositionand/or oxygenation. After cleaned, the said gaseous mixture isdischarged from the said heating source region through filters. In thiscase, both of the heating sources are gas ranges, the said heatingsource regions are two separate gas combustion regions.

DETAILED DESCRIPTION OF THE INVENTION

[0027] As shown in FIG. 1, the principle of the present invention can bedescribed as follows. Cooker 1 is placed over oven 2. Edible oil 3 isheated in the cooker 1. The cooker 1 is heated by gas flame. The gas isprovided by gas range 4 through gas pipe 5 and valve 6. The oily smoke,fumes, vapor or odors and a part of air will be mixed to become agaseous mixture and drawn into hood 7, then entered flexible pipe 8under the action of drawing fan 9. The drawing fan is driven by electricmotor 10 and controlled by switch 11. The needed electric power isprovided through power cord 12. After passing through pipe 8, the saidgaseous mixture is forced to enter pipe 13. After passing through pipe13, the said gas mixture is forced to enter the preheating region 14.The gas range 4 is surrounded by the preheating region 14, through whichthe heating source region, i.e. the gas combustion region 15 is formedbetween the gas range and the preheating region. After preheated in thesaid preheating region, the said gaseous mixture is forced to enter thesaid gas combustion region 15. In the said gas combustion region ahigher temperature can be maintained due to the combustion of gas. Apart of combustion thermal energy can be used to preheat the saidgaseous mixture filling in the preheating region 14. A part ofcombustion thermal energy can be used to initiate and/or accelerate thedecomposition and/or oxygenation of the pollutants contained in the saidgaseous mixture. If the temperature of the said gaseous mixture fillingin the said gas combustion region 15 is high enough, the decompositionand/or oxygenation of pollutants can carried out fully and completely.Then, the harmless products of these reactions and un-reacted matterscontained in the said gaseous mixture, such as nitrogen, will bedischarged from the said gas combustion region 15 by passing throughfilter 16. After finishing the cooking, the gas pipe valve 6 will closeand the combustion of gas will stop. However, the drawing fan 9 willcontinue to work for a while to draw the remains of oily smoke, fumes,vapor or odors coming from cooker 1. When the said remains enter thesaid gas combustion region 15, the after-heat in the region willcontinue to help the decomposition and/or oxygenation of the remains.Finally, the electric power switch 11 will turn off and the drawing fan8 will stop.

[0028] The function of the high temperature in the said heating sourceregion is to initiate, guarantee or promote the decomposition and/oroxidizing reactions of the pollutants. The higher the temperature is,the more completely the reactions will be carried out, and the biggerthe reaction rates will be. In general, the temperature in the regionshould not be lower than about 200° C. As we all know that the maincomposition elements in many organic substances, including all kinds ofedible oils, are hydrogen, oxygen and carbon. The general formula ofpure nature edible oil can be written as

[0029] Here R, R′ and R″ denote different hydroxyl groups composed ofcarbon and hydrogen atoms. Therefore, the oil smoke, fumes, vapor, odorsor other pollutants produced from the heated edible oil and allintermediate products of the decomposition reactions of edible oil areall composed of carbon, hydrogen and oxygen atoms. If these substancescan be oxidized completely in the said heating source region, the finalresultants discharged from the said heating source region will be waterand carbon dioxide. The un-acted nitrogen contained in the said gaseousmixture will also be discharged at the same time. The basic oxidizationreaction formula of these substances can be written as

C_(x)H_(y)O_(z)+(x+y/4)(O₂+3.76N₂)=xCO₂ +y/2H₂O+(3.76x+0.94y)N₂  (1)

[0030] Here x, y and z denote the numbers of carbon, hydrogen and oxygenatoms in the organic substance respectively. The above reaction is anexothermic reaction. The thermal energy provided from the reaction ishelpful to keeping the high temperature in the said heating sourceregion. However, if the oxygen is not enough, a certain amount of carbonmonoxide may produce based on the following reaction.

C_(x)H_(y)O_(z)+[(x+w)/2+y/4](O₂+3.76N₂)=(x−w)CO₂+wCO+y/2H₂O+[1.88(x+w)+0.94y]N₂  (2)

[0031] in which w denotes the molar number of the carbon monoxide.Carbon monoxide is very harmful, by using powerful drawing fan thepresent invention can guarantee the full supply of oxygen. A greatquantity of oxygen entered the heating source region can also accelerateand improve the combustion of gas, fuel oil or coal when the heatingsource of the oven is gas, fuel oil or coal range.

[0032] A series of composition analyses on the air near the inlet ofhood 7 and the outside of the said filter 16 have been done. The resultsshow that the purification effect depends mainly on the temperature T ofthe said gas combustion region, the duration t that the gaseous mixturekeeping in the region and the relationships between T and t. Forexample, if the cooker is larger, the amount of the edible oil is moreor the temperature of the oil is higher, the amount of the oily smokemust be more than that when using a smaller cooker containing little oilwith a lower temperature. Thus more powerful drawing fan is needed todraw the more oily smoke efficiently. However, due to the faster flowspeed of the gaseous mixture, t will be shortened. In order to guaranteea complete purification of oily smoke, T should be higher, for which thegas valve 6 should open bigger. In general, the more the amount of theoily smoke, fumes, vapor or odors is, the bigger the gas flow should be,the higher power of the drawing fan should be and the higher thetemperature T will be. Experiments show, provided having the suitable Tand t, the gaseous mixture discharged from the heating source regioncontains little oil smoke, fumes, vapor, odors, or other pollutants.However, if the flow of the gaseous mixture in pipe 13 is too bigger andthe flow of gas in gas pipe 5 is too small, the combustion will not begood because the combustion of gas will be interfered even the flame canbe distinguished by the bigger flow coming from the preheating region14. Therefore, controlling the flow of gas and the power of drawing fanis important. The following Table (1) shows several experimental resultscorresponding to various drawing fan powers. TABLE (1) Edible oil purecorn oil pure corn oil pure corn oil Oil temperature 120° C. 135° C.155° C. Motor power 10 W 15 W 20 W Temperature of >200° C. >235°C. >250° C. heating source region Concentration (mol/cm³) of substancescontaining in the discharged gaseous mixture: Oil vapor 1.1 × 10⁻⁵ 2.7 ×10⁻⁵ 0.5 × 10⁻⁵ Carbon monoxide 0 0 0 Oxides of nitrogen 0 0 0 Otherpollutants 0 0 0

[0033] In this design, the pipe 13 has an extra function. It can be usedas a supporting arm to support the weight of hood 7, drawing fan 9,motor 10, switch 11 and the flexible pipe 8. The said flexible pipe 8can be lengthen and shorten easily to adjust the height of hood 7 forsuiting various cooking operations.

[0034] Based on the above principle and experiments, the presentinvention has the following advantages compared with existing oily smokeexhausters. First, it is not necessary to assembly a pipe system forconnecting the exhauster with chimney or sewer. The gaseous mixturepurified by the device designed based on the present invention can bedischarged indoors, which is very convenient to Chinese, Vietnamese,Thailand or other Asian people who like fried food when they design,purchase or rent houses. Second, due to the omission of the pipe system,the distance from the drawing fan to the cooker can be adjusted by handvery easily. So the oily smoke, fumes, vapor or odors can be drawn morecompletely. Also, the cooking operation will not be affected accordingto the present invention. The third advantage is that the serious airand water pollution caused due to using the existing exhausters can beavoided by using the present invention. One does not worry whether theoily smoke or irritative gases will enter his or her neighbors' houses.Due to without complex pipe system, the device design based on thepresent invention can be moved to different oven easily. Due to withoutthe long and complex pipe system, the drawing fan can be designed havinga lower power, so the noise caused by the drawing fan can be reducedgreatly. Especially, most of oily smoke can be oxidized into carbondioxide and water. Only the internal surface of the said hood needs tobe cleaned after the device was used for a period. But the hood can bedismounted and assembled so easily that the users can do the workthemselves and do not ask professional people to help them. So the cleanwork is no longer time-consuming, labor-some and expensive when usingthe present invention. Finally, the present invention provides a safeand energy-saving method for treating oily smoke, fumes, vapor or odors.It does not need any special or extra heating source. In fact, thecombustion of gas, fuel oil or coal of ovens can be improved if we canprovide a suitable power of drawing fan and a suitable flow of gas orfuel oil.

[0035]FIG. 2 shows some details of the preheating region, gas combustionregion and gas range of the device shown in FIG. 1. It is a longitudinalsection view. The gaseous mixture of air, oily smoke, fumes, vapor orodors is forced to enter the preheating region, i.e. preheating pipe 1after passing through pipe 2. There are a series of holes (one of themis marked with 3) located uniformly on the wall of the said preheatingpipe. After preheated in pipe 1, the said gaseous mixture will enter thegas combustion region 8 by passing through the holes 3. The gas providedby gas range 4 will enter the said gas combustion region 8 by passingthrough the gas holes (one of them is marked with 5), and then bum inthe said gas combustion region. Under the high temperature, thepollutants contained in the said gaseous mixture can be decomposedand/or oxygenated in the said gas combustion region, the products ofthese reactions and un-reacted matter contained in the gaseous mixturewill be discharged from the said gas combustion region by passingthrough a number of small holes (one of them is marked with 6) which arelocated on the wall of a metal supporting ring 7. The said supportingring has two functions. One is for supporting the cooker. Another one isfor filtering the said gaseous mixture discharged from the said gascombustion region. Therefore, the said supporting ring is also a filter.In this design, the said preheating pipe 1 has three functions. First,it can be used to transfer the thermal energy coming from the heatingsource for preheating the gaseous mixture filling in the said preheatingpipe. Secondly, it can be used to provide a uniform distribution of thegaseous mixture flow when entering the gas combustion region. Finally,most of the said gaseous mixture can be guaranteed to enter the said gascombustion region not leak out.

[0036]FIG. 3 shows another design based on the present invention.Compared with FIG. 1, the only difference in this design is that thesaid gaseous mixture drawn by the drawing fan 9 from the cooker 1 willbe forced to enter two preheating regions 14 and 17 by passing throughpipe 8 and pipe 13. The two preheating regions surround two gas ranges 4and 18 separately to form two gas combustion regions 15 and 19 on oven.As shown in FIG. 1, the pollutants contained in the preheated gaseousmixture can be decomposed and/or oxygenated in the two gas combustionregions. Then, the cleaned gaseous mixture is discharged from the twogas combustion regions by passing through filter 16 and 20 separately.The pollutants contained in the said gaseous mixture can be removed morecompletely by using two heating source regions, but the construction ofthe device will be more complex. In this design, the gas range 18 can beused for heating water or other cooking operations without oily smoke,fumes, vapor or odors.

What I claimed as my invention is:
 1. A method for treating and removing oily smoke, fumes, vapor, or odors. According to this method, the oily smoke, fumes, vapor or odors produced from at least one cooker placed over an oven are drawn by at least one drawing fan and mixed with a part of air to become at least one gaseous mixture under the action of the said drawing fan. Then, the said gaseous mixture of air and oily smoke, fumes, vapor or odors is forced to pass through at least one passage and then enter at least one preheating region. In the said preheating region, the said gaseous mixture is preheated. After preheated, the said gaseous mixture is forced to enter at least one heating source region of the said oven. A part of thermal energy provided by the heating source located in the said heating source region is used for preheating the said gaseous mixture filling in the said preheating region. A part of thermal energy provided by the said heating source is used for initiating and/or accelerating the decomposition and/or oxygenation of the pollutants contained in the said gaseous mixture filling in the said heating source region. Then, the products of the said decomposition and/or oxygenation reactions and the un-reacted matter contained in the said gaseous mixture are discharged from the said heating source region by passing through at least one filter.
 2. A method for treating and removing oily smoke, fumes, vapor, or odors as claimed in claim 1, wherein the said heating source is a gas range and the said heating source region is a gas combustion region.
 3. A method for treating and removing oily smoke, fumes, vapor, or odors as claimed in claim 1, wherein the said heating source is a fuel oil range and the said heating source region is a fuel oil combustion region.
 4. A method for treating and removing oily smoke, fumes, vapor, or odors as claimed in claim 1, wherein the said heating source is a coal range and the said heating source region is a coal combustion region.
 5. A method for treating and removing oily smoke, fumes, vapor, or odors as claimed in claim 1, wherein the said heating source is an electric range and the said heating source region is an electrically heating region.
 6. A method for treating and removing oily smoke, fumes, vapor, or odors as claimed in claim 1, wherein the said passage is a pipe, through which the said gaseous mixture of air and oily smoke, fumes, vapor or odors drawn by the said drawing fan can enter at least one said preheating region.
 7. A method for treating and removing oily smoke, fumes, vapor, or odors as claimed in claim 1, wherein the said heating source is surrounded with the said preheating region. The said heating source region is formed between the said heating source and the said preheating region.
 8. A method for treating and removing oily smoke, fumes, vapor, or odors as claimed in claim 7, wherein the said heating source region and said preheating region are connected through a series of holes. 